These are comparable to type R and RST, except the outer case does not have a metal reinforcement ring. To compensate, the outside is not made of normal rubber, but a hard, heavy-duty rubber fabric. The advantage is that these types can be made in a split version. They are almost always produced to order, and made of NBR or FKM.
• Lubricating oil
• Rotational speed
• Shaft diameter, etc.

Material selection is important to the life of a radial shaft seal. The elastomer’s resistance to temperature, abrasion, chemicals, weather, sunlight, and ozone can affect a profile’s longevity and performance. The two most prevalent materials are Nitrile and Viton. See our Oil Seal Materials page for details on compounds and chemical compatibility.
Oil seal type or shape
Loosen the securing-clamp bolt at the base of the distributor, then carefully withdraw the distributor.
Figure 5 explains the JTEKT seal numbering system.
Seal numbers consist of
(1) the seal type code,
(2) the spring code,
(3) the lip type code,
(4) the dimensional numbers, and
(5) the special type code,
and Table 6 shows examples of each of these codes/numbers.

Crankshaft front seal
Explore All About Industrial Oil Seals
It is important to choose the right type of oil seal for a given application, as it may need to address specific operational concerns such as:
1
internal, external and axial orientation
Use a piece of wood to scrape off all traces of the old gasket from the head and cover. If total removal proves difficult, use a broad screwdriver blade, but take care not to scratch the seating.